Methods and apparatus for the edge grinding of non-circluar glass panes generally make use of a rotating grinding wheel--usually a diamond wheel--which is brought into contact with the glass pane. The grinding point between the wheel and the glass pane travels along the edge of the rotating wheel while a coolant jet is directed tangentially onto the grinding wheel to provide the cooling effect. The grinding wheel is supported on a spindle whose spindle arm is connected to an automatic control unit to adjust the position of the grinding wheel with respect to the glass pane.
Such an apparatus is known in various designs, e.g. from the German publication DE-OS No. 28 17 397 or European patent EP-A No. 00 71 541. A main concern in such an apparatus is a proper cooling as it affects the service life of the grinding wheel as well as the quality of the grinding process.
A device for supplying a coolant is known in practice which includes a circularly bent pipe connected to a distributor box. For discharging the coolant, the pipe and the distributor box are provided with a plurality of nozzle bores or inserted nozzles, not all of which are directed tangentially towards the grinding wheel.
The cooling effect provided with such a device has proven to be unsatisfactory. Especially when the grinding point travels in a manner as previously mentioned, the cooling effect deteriorates considerably as the coolant jet will not sufficiently be directed towards the grinding point. By increasing the amount of injected coolant, the cooling effect may somewhat be improved, however, such increase is generally not desired because of e.g. economical reasons.